Replacing a Gate Valve: A Professional Guide
If you have prehistoric gate valves attached to the skin fittings on your vessel, it’s time to consider replacing them with ball valves or seacocks.
Types of Valves
Gate Valves
The gate valve was once a standard fixture but they are now obsolete. Replacing them with modern alternatives is crucial for your vessel’s safety and efficiency. A gate valve typically has a pipe thread instead of the straight thread standard on a skin fitting, creating a weak point. Additionally, the stems, usually made of yellow brass, are prone to dezincification.
In-Line Ball Valves
In-line ball valves are supported entirely by the skin fitting. They clearly indicate if the valve is open or shut and require only a quarter turn, unlike the multiple 360° turns needed for a gate valve. Replacing a gate valve with an in-line ball valve provides ease of use and eliminates the risk of accidental damage.
Flanged Seacocks
Flanged seacocks offer more strength and support than in-line valves. They have a flanged base and are secured with thru-bolts, preventing loosening. However, they may not fit in smaller vessels due to space constraints or uneven bilges. In such cases, an in-line ball valve is a viable backup. Flanged seacocks that can be disassembled for cleaning provide a clear advantage, making them an excellent choice when replacing a gate valve.
Benefits of Modern Valves
The description of gate valves above highlights why they are no longer used in new boats. Replacing them with modern ball valves or flanged seacocks ensures better functionality, durability, and safety.
